ELEMENTARY ANA TO MY, 



[LESS. 



man shares with his class, but which may have no distinct 

 representative in non-mammalian forms which are higher 

 than Batrachians, e.g. in the Iguana. 



The splenius colli is present only in a few Mammals. 



The erector spines presents in man a degree of differentia- 

 tion not generally found in animals below his class. Thus in 

 the Iguana and Chameleon it is but divisible into the longi- 

 tudinal parts answering respectively to the longissimus aorsi 



FIG. 290. DEEPER MUSCLES OF OUTER SIDE OF HINDER PART OF TRUNK AND 

 ANTERIOR PART OF TAIL, AND OF THE DORSAL (EXTENSOR) SlDE OF RlGHT 

 PELVIC LIMB OF Menobranchus the gluteus maximus, rectus femoris, and 

 extensor longus digltorum being cut and reflected. 



EH, extensor hallucis ; ELD, extensor longus digitorum ; ExO, external 

 oblique ; PC, femoro-caiidal ; G, gracilis ; GMd, gluteus medius ; GMi, 



fluteus minimus ; GMx and R F, great extensors of thigh ; /, iliacus (?); 

 1C, ilio caudal ; IP, iiio-peroneal ; S, sartorius ; SJlf, semi-membranosus ; 

 ST, semi-tendinosus ; TA and TA I , tibialis anticus. 



and sacro lumbalis, and continuing, with the intervention of 

 certain neck muscles, from the cranium to the end of the 

 dorsum of the tail. But a greater simplicity still may exist, 

 as in Tailed-Batrachians (e.g. Menopoma and Menobranchus), 

 where, without the intervention of any such neck muscles, a 

 simple, or more or less tendinously intersected muscular mass 

 extends from the skull directly to the end of the dorsum of 

 the tail. This dorsal muscle mav be reduced to a mere rudi- 



